1. Field of the Invention
The present invention relates, in general, to optical cable identification, and, more particularly, to an optical cable identification apparatus and method capable of accurately identifying an optical cable from a remote location. Here, the remote location means a place, such as a manhole, which is remote from a telephone station, at which communication devices are located.
2. Description of Related Art
Generally, telephone lines or the other types of communication lines connect telephone stations, and a plurality of manholes is formed between the telephone stations so that operations, such as maintenance and modification, can be easily performed.
In reality, in the case of a manhole in which a plurality of strands of optical cables is installed, such an optical cable is often required to be divided or moved. In this case, a desired optical cable must be cut. If the cable to be worked on is misjudged, there is the possibility that a cable line being used for communication may be cut. Therefore, it is important to reliably identify a cable to be worked on before a cutting operation is performed.
In order to identify the cable to be worked on, a method of pulling a cable using physical force from an adjacent manhole and a method of using electromagnetic induction have been used. When the electromagnetic induction method is applied to identify one of optical cables, metal tension yarns capable of transmitting electricity must be included in respective cables. However, general optical cables which are currently used pose a difficulty in that they have no such tension yarn. In addition, since tension yarns passing through manholes may not be connected to one another, this method has a limitation in the distance over which it can be implemented.
In order to solve the above-described inconvenience, there is a prior art interferometer method of accurately identifying an optical cable by connecting two strands of optical fibers in a loop form. However, in this case, there is inconvenience in that two strands of optical fibers in a cable desired to be identified must be used, and in that the two strands of optical fiber must be connected to at the opposite end of the cable so as to form a loop. In particular, when an end of an optical cable or an optical fiber is not found, a loop cannot be configured, and thus the interferometer method cannot be applied.